Push lock pipe connection system

ABSTRACT

A pipe for connecting to a similar adjacent pipe. The pipe has a female end with a plurality of rigid fingers extending into the space within the female end. The plurality of rigid fingers extends from at least one interior circumferential groove on the interior surface of the female end. On the male end of the pipe there is at least one exterior circumferential groove that is sized and positioned to receive the plurality of rigid fingers from a corresponding interior circumferential groove on the female end of an adjacent pipe. The number of interior circumferential grooves on the female end with the plurality of rigid fingers extending from them typically corresponds to the number of exterior circumferential grooves on the male end. When the male end of a similar adjacent pipe is inserted into the female end of the pipe, the plurality of rigid fingers is received within the corresponding exterior circumferential groove on the male end, thereby preventing the male end of the similar adjacent pipe from being withdrawn from the female end of the pipe.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/365,000 filed Feb. 3, 2009 entitled “Push Lock Pipe ConnectionSystem” which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to pipe connections and methodsof securely connecting pipes, regardless of the material from which theconnecting pipes are manufactured. More specifically, the preferredembodiment of the present invention relates to connection system thatuses a plurality of rigid locking fingers extending from the interiorsurface of a female end of the pipe and corresponding locking grooves onthe exterior surface of a male end of the pipe for receiving rigidlocking fingers from a connecting length of pipe. The present inventionoffers a quick connection of two lengths of pipe without gluing,threading, or welding, as well as other advantages described herein. Theconnection system can be implemented into lengths of pipe through amanufacturing process so that the end product is an entire product lineof pipe that employs the present connection system.

2. Description of the Related Art

In piping systems, there is a variety of ways to connect or join twoseparate lengths of pipe. In general, connections between two lengths ofpipe traditionally have been achieved through one of four ways: (1)gluing or cementing; (2) welding; (3) threading; or (4) externalconnections such as collars and flanges. In gluing or cementing, anadhesive is applied to the male end, to the female end, or to both endsof the pipes being joined. The male end of one pipe is inserted into thefemale end of the adjacent pipe being joined and the adhesive cures,permanently joining the pipes. With welding, two metal pipes are joinedusing molten metal. In threading, the male end of a pipe has externalthreads and the female end of the adjacent pipe has internal threads.The male end is inserted into the female end of the adjacent pipe, thepipes are rotated, and the threads engage each other. With externalconnections such as collars and flanges, some sort of threaded fastenerinteracts with the external connecting structure to securely lock theconnection between the two pipes.

Each of the aforementioned connection types has certain disadvantages.For example, a glued or cemented connection can be cumbersome and timeconsuming. The pipe surfaces must be cleaned and the adhesive appliedand allowed to cure before the connection can withstand tensile force.Further, the pipes cannot be disconnected without ruining them. Inthreaded connections, which also can be achieved quickly, the pipesusually can be disconnected and reused, but the threaded connectioncannot withstand high tensile forces. Welded connections can withstandsignificant tensile forces, but can only be used on metal pipes.Further, creating the weld is a time-consuming task, and, once the weldis formed it is difficult to remove and may not be possible withoutruining the pipes. With external connections, the connection often canbe removed and can withstand significant tensile forces, but forming theconnection is also a time-consuming task.

It is therefore desirable to provide a type of pipe that allows aconnection that will withstand large tensile forces and can be quicklyformed with similar adjacent pipes. It is also desirable to provide aconnection that can withstand large tensile forces yet be easilydisconnected, with the proper tool. It is a further object of thepresent invention to provide a connection that can be achievedregardless of the material from which the pipe is made.

BRIEF SUMMARY OF THE INVENTION

The pipe of the present invention provides the advantage of a connectionthat can be quickly formed between pipes of the same or differentmaterials. In addition, the connection formed between two similar,adjacent pipes may have a comparatively high tensile yield strength.

The pipe of the present invention has a female end for receiving a maleend of a similar adjacent pipe. The interior surface of the female endhas interior circumferential grooves and the exterior surface of themale end has corresponding exterior circumferential grooves. When themale end of the similar adjacent pipe is fully inserted into the femaleend, rigid fingers extending from the interior circumferential groovesare received within the exterior circumferential grooves and prevent themale end from be withdrawn.

The female end of the pipe has a female leading edge and an interiorsurface, which defines a male end receiving chamber within the femaleend. The male end receiving chamber will ultimately receive the male endof the similar adjacent pipe. The interior surface of the female end hasat least one and preferably a plurality of interior circumferentialgrooves disposed on it. Rigid fingers extend from these interiorcircumferential grooves into the male end receiving chamber. Preferably,the rigid fingers extending from each interior circumferential grooveare connected to a band seated within each of the interiorcircumferential grooves.

The male end of the pipe has a male leading edge, which leads the maleend into the male end receiving chamber of the female end of a similaradjacent pipe. The male end has an outer circumference which is smallerin diameter than the diameter of the male end receiving chamber on thefemale end. Disposed on the exterior surface of the male end are atleast one and preferably a plurality of exterior circumferentialgrooves. The number of exterior circumferential grooves will typicallycorrespond to the number of interior circumferential grooves disposed onthe interior surface of the female end of a similar adjacent pipe.

The exterior circumferential grooves on the male end are configured toreceive the rigid fingers extending into the male end receiving chamberof the female end on a similar adjacent pipe. During the insertion ofthe male end into the male end receiving chamber, the rigid fingers aredisplaced toward the interior surface of the female end so that the maleend can be fully inserted into the female end. When the male end isfully inserted into the male end receiving chamber the rigid fingersextending from the interior circumferential grooves on the female endare positioned within corresponding exterior circumferential grooves onthe male end. The rigid fingers and their positioning within thecorresponding exterior circumferential grooves prevent the male end frombeing withdrawn.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of the preferred embodiment ofthe present invention, as shown with the female end of one pipe and themale end of a similar adjacent pipe.

FIG. 2 is a cross sectional side view of the preferred embodiment forthe present invention taken along the female end of one pipe and themale end of a similar adjacent pipe.

FIG. 3 a cross sectional side view of the preferred embodiment for thepresent invention taken along the female end of one pipe and the maleend of a similar adjacent pipe, with the male end being partiallyinserted within the female end.

FIG. 4 is a cross sectional side view of the preferred embodiment forthe present invention taken along the female end of one pipe and themale end of a similar adjacent pipe, with the male end being fullyinserted within the male end receiving chamber and the plurality ofrigid fingers being positioned within their corresponding exteriorcircumferential grooves.

FIG. 5 is a cross sectional view showing the side profile of thepreferred interior circumferential groove on the female and a fingerfrom the plurality of fingers extending from a band seated within thegroove.

FIG. 6 is a cross sectional view showing the side profile of thepreferred exterior circumferential groove on the male end.

FIG. 7A is a back side view of a portion of a set of rigid fingersextending from the band that is present in the preferred embodiment.

FIG. 7B is a front side view of a portion of a set of rigid fingersextending from the band that is present in the preferred embodiment.

FIG. 7C is a side view taken along section line 7C-7C from FIG. 7B thateffectively shows the preferred embodiment of a single finger from a setof rigid fingers, with the finger extending from the band that ispresent in the preferred embodiment.

FIG. 8 is a cross sectional side view showing alternative embodimentsfor the present invention taken along the female end of one pipe and themale end of a similar adjacent pipe, with the male end being fullyinserted within the female end and the plurality of rigid fingers beingpositioned within their corresponding exterior circumferential grooves.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 through 4, the preferred embodiment of the presentinvention is shown with a pipe 10 and a similar adjacent pipe 12. Inpractice, the pipe 10 has the same structure as the similar adjacentpipe 12 and therefore, a description of structure that is present forthe similar adjacent pipe 12 in the Figures applies equally to adescription of the structure for the pipe 10, and vice versa.

Pipe 10 has a female end 14, an intermediate length 16, and a male end18. Referring to FIGS. 1 and 2, the female end 14 has an interiorsurface 20 and a female leading edge 22 that terminates the female end14. Although not shown in FIGS. 1-4, it is anticipated that the femaleleading edge 22 could be beveled. The interior surface 20 of the femaleend 14 defines a male end receiving chamber 24, which is essentially theinterior space within the female end 14. The male end 18 of the pipe 10has a male leading edge 26 and an exterior surface 28 with acircumference that is smaller in diameter than diameter of the male endreceiving chamber 24 on the female end 14. Preferably, the male endreceiving chamber 24 will ultimately receive the male end 18 of thesimilar adjacent pipe 12 with minimal clearance when the pipes areconnected. The pipe 10 is sized according to the outer diameter of itsintermediate length 16 and has a tensile yield strength that is largelydependent on the material from which pipe 10 is made.

A stop member 30 is disposed within the pipe 10 preferably at theinterior end of the male end receiving chamber 24. In the preferredembodiment, as shown in FIGS. 1-4, the diameter of the male endreceiving chamber 24 is larger than the interior diameter of theintermediate length 16. As such, the stop member 30 in the preferredembodiment is a circumferential shoulder formed by the reduction indiameter from the male end receiving chamber 24 to the interior diameterof the intermediate length 16. Additionally, in the preferredembodiment, at least one circumferential sealing groove 32 with anO-ring 34 seated therein is disposed on the interior surface 20 of thefemale end 14. However, it is anticipated that in certain applicationsthe circumferential sealing groove 32 and the O-ring 34 may not bepresent.

The interior surface 20 of the female end 14 has a plurality of interiorcircumferential grooves 36 disposed on it. In the preferred embodiment,the number of interior circumferential grooves 36 is four. However, itis anticipated that this number could be more or less and even as few asone, depending upon the application.

A plurality of sets of rigid fingers 38 extend from each of the interiorcircumferential grooves 36 and into the male end receiving chamber 24,forming an acute angle α between each of the rigid fingers 38 and theinterior surface 20 of the female end 14 and directed away from thefemale leading edge 22 (see FIG. 5). In the preferred embodiment, theangle α formed between each of the rigid fingers 38 and the interiorsurface 20 measures between 27° and 30° inclusive.

Although rigid, each of the rigid fingers 38 is displaceable and can beradially displaced toward and away from the interior surface 20 of thefemale end 14. Further, each of the rigid fingers 38 is biased toward anon-displaced position (as shown in FIG. 7C) in the male end receivingchamber 24 unless acted upon by some force. Preferably, the rigidfingers 38 are made of stainless steel. However, any number ofsubstantially rigid materials could be used, depending on theapplication and the tensile forces involved. In the preferredembodiment, each set of rigid fingers 38 extends from a band 40 (seeFIGS. 7A, 7B, & 7C) that is seated within each of the interiorcircumferential grooves 36.

As shown in FIG. 5, in the preferred embodiment, the interiorcircumferential grooves 36 have a generally rectangular cross sectionprofile with a first side wall 50, a second sidewall 52, a bottomsurface 54, and a shoulder 56 positioned adjacent the first side wall50. The shoulder 56 has a top surface 58 and a side surface 60. In thisembodiment, the band 40 is seated between the second sidewall 52 of theinterior circumferential grooves 36 and the side surface 60 of theshoulder 56 such that the rigid fingers 38 extend above and over theshoulder 56. When the male end 18 is inserted into the female end 14,the minimal clearance there between will cause each set of rigid fingers38 to be displaced at least partially, if not totally, into the interiorcircumferential grooves 36. In this regard, the distal end 48 of each ofthe rigid fingers 38 (see FIGS. 7A, 7B, & 7C) displaces into the spacebetween the top surface 58 of the shoulder 56 and the top edge of thefirst sidewall 50 of the interior circumferential grooves 36

Disposed on the exterior surface 28 of the male end 18 is a plurality ofexterior circumferential grooves 42 with each groove having a sidewall44 at the side of the groove nearest the male leading edge 26. A bottomsurface 46 extends from the bottom edge of the sidewall 44 and slopes atan angle to the exterior surface 28 of the male end 18, forming an acuteangle with the exterior surface 28 (see FIG. 6). Preferably, the angle βformed between the bottom surface 46 of the exterior circumferentialgrooves 42 and the exterior surface 28 of the male end 18 isapproximately 16°. As a result, in the preferred embodiment the exteriorcircumferential grooves 42 have a triangular cross section profileformed by the sidewall 44 and the bottom surface 46. Preferably, thenumber of exterior circumferential grooves 42 on the male end 18 willcorrespond with the number of interior circumferential grooves 36 on theinterior surface 20 of the female end 14.

FIG. 3 shows the male end 18 of the similar adjacent pipe 12 partiallyinserted into the male end receiving chamber 24 of the female end 14 ofthe pipe 10. As shown, the male leading edge 26 of the male end 18 isbeveled in the preferred embodiment of the pipe 10, with the bevel beingset at an approximately 20° radially inward angle with respect to theexterior surface 28 of the male end 18. The angling of the rigid fingers38 away from the female leading edge 22 allows the male end 18 to beinserted into the male end receiving chamber 24, and, the insertion isfacilitated by the bevel at the male leading edge 26 as well as thetriangular cross section profile of the exterior circumferential grooves42. As the male end 18 is inserted, the exterior surface 28 of the maleend 18 contacts the sets of rigid fingers 38 and causes the rigidfingers 38 to be displaced toward the interior surface 20 of the femaleend 14.

FIG. 4 shows the male end 18 of the similar adjacent pipe 12 fullyinserted into the male end receiving chamber 24 on the female end 14 ofthe pipe 10. When fully inserted, the male leading edge 26 abuts thestop member 30. With the male end 18 fully inserted into the female end14 the sets of rigid fingers 38 are positioned over their correspondingexterior circumferential grooves 42 on the male end 18, allowing eachset of rigid fingers 38 to spring back toward its non-displaced positionsuch that the rigid fingers 38 are received within the correspondingexterior circumferential grooves 42 on the exterior surface 28 of themale end 18. Preferably, a set of the rigid fingers 38 becomespositioned within each exterior circumferential groove such that adistal end 48 (see FIGS. 7A, 7B, & 7C) of each of the rigid fingers 38abuts the sidewall 44 of the exterior circumferential grooves 42. Theabutment of the distal ends 48 of the rigid fingers 38 against thesidewall 44 prevents movement of the male end 18 of the similar adjacentpipe 12 out of the male end receiving chamber 24 of the female end 14 ofthe pipe 10, thereby locking the pipe 10 and the similar adjacent pipe12 together.

FIGS. 7A & 7B show a portion of a set of rigid fingers 38 extending fromthe band 40. As noted, in the preferred embodiment the band 40 is seatedbetween the second sidewall 50 of the interior circumferential grooves36 and the side surface 60 of the shoulder 56.

FIG. 7C shows a side view of a set of rigid fingers 38 along sectionline 7C-7C in FIG. 7B and effectively illustrates the side profile of asingle finger extending from the band 40. The finger extends from theband 40 through a bend 62. The bend 62 causes the rigid fingers 38 toextend out of the interior circumferential grooves 36 and into the maleend receiving chamber 24 at the acute angle α away from the femaleleading edge 22, as shown in FIG. 5.

The number, shape, and size of rigid fingers 38 in each set of rigidfingers 38 is a design choice that depends on the application of theinvention. With a 4.5 inch PVC pipe, the preferred embodiment of thepresent invention has 135 stainless steel fingers in each set, with oneset per interior circumferential groove. Each of the rigid fingers 38 is0.060 inches wide and the sets of rigid fingers 38 have a 0.060 inch gapbetween each finger. The band 40 is approximately 0.155 inches long fromits bottom edge to the bend 62, and the rigid fingers 38 areapproximately 0.209 inches long from the bend 62 to their distal ends48.

As noted and shown in FIGS. 5 & 6, in the preferred embodiment the acuteangle α created between the interior surface 20 of the female end 14 andthe rigid fingers 38 is larger than the angle β between the bottomsurface 46 of the exterior circumferential grooves 42 and the exteriorsurface 28 of the male end 18. As a result, the rigid fingers 38 biasagainst the bottom surface 46 of the exterior circumferential grooves 42when fully received therein and will exert a continuous radially inwardforce on the bottom surface 39.

FIG. 8 shows an alternative embodiment having a different type ofconnection than the connection present in the preferred embodiment. Theconnection shown in FIG. 8 is referred to as a “Flush Mount” connectionbecause the outer diameter of the female end 14 is substantially equalto the outer diameter of the intermediate length 16 between the male end18 and the female end 14. In the Flush Mount connection, the male endreceiving chamber 24 still has a diameter that is greater than theinterior diameter of the intermediate length 16, but the male endreceiving chamber 24 is formed by machining out the chamber and not bybelling the female end 14 with a mandrel.

FIG. 8 also shows different embodiments of the invention that can bepresent regardless of whether a Flush Mount connection is used. Forexample, one aspect that differs from the preferred embodiment is theinterior circumferential grooves 42 do not have a shoulder 56.Consequently, each band is wider and is seated between the sidewalls ofeach of the interior circumferential grooves 42. Another aspect thatdiffers from the preferred embodiment is that the male leading edge 26is not beveled in FIG. 8. Finally, FIG. 8 shows the alternativeembodiment where the bottom surface 46 of the exterior circumferentialgrooves 42 is not angled and the exterior circumferential grooves 42have a substantially rectangular cross section profile.

Although the present invention has been described with reference tospecific embodiments, this description is not meant to be construed in alimiting sense. Various modifications of the disclosed embodiments, aswell as alternative embodiments of the invention will become apparent topersons skilled in the art upon the reference to the above-descriptionof the invention. It is, therefore, contemplated that the appendedclaims will cover such modifications that fall within the scope of theinvention.

The invention claimed is:
 1. A method of connecting a female end of apipe to a male end of a similar adjacent pipe, the method comprising:seating a band in an interior circumferential groove on the interiorsurface of said female end of said pipe, wherein a plurality of rigidfingers extends from said band; extending said plurality of rigidfingers from said interior circumferential groove into a male endreceiving chamber of said female end; receiving said male end of saidsimilar adjacent pipe within said male end receiving chamber of saidfemale end of said pipe; engaging said plurality of rigid fingers withsaid male end of said similar adjacent pipe; displacing said pluralityof rigid fingers toward the interior surface of said female end of saidpipe; positioning an exterior circumferential groove on said male endwith respect to said plurality of rigid fingers; and receiving at leasta portion of said plurality of rigid fingers into said exteriorcircumferential groove on said male end.
 2. The method of connecting afemale end of a pipe to a male end of a similar adjacent pipe as recitedin claim 1 wherein preventing said male end of said similar adjacentpipe from being withdrawn from said female end of said pipe furthercomprises engaging distal ends of said plurality of rigid fingersagainst a sidewall of said exterior circumferential groove of said maleend.
 3. The method of connecting a female end of a pipe to a male end ofa similar adjacent pipe as recited in claim 1, further comprisingpreventing the male end of said similar adjacent pipe from insertingfarther into said pipe.
 4. The method of connecting a female end of apipe to a male end of a similar adjacent pipe as recited in claim 3wherein preventing said male end of said similar adjacent pipe frominserting further into said pipe further comprises engaging said maleend of said similar adjacent pipe with a stop member positioned on theinterior surface of said female end of said pipe.
 5. The method ofconnecting a female end of a pipe to a male end of a similar adjacentpipe as recited in claim 1, further comprising preventing said male endof said similar adjacent pipe from being withdrawn from said female endof said pipe.
 6. The method of connecting a female end of a pipe to amale end of a similar adjacent pipe as recited in claim 1, wherein saidinterior circumferential groove on said interior surface of said femaleend of said pipe is formed with a bottom surface, a first side wall, asecond sidewall opposite said first sidewall, and a shoulder having atop surface that meets said first side wall and a third side surfacethat meets said top surface and said bottom surface, wherein each fingerof said plurality of rigid fingers includes a free distal end extendingoutside of said interior circumferential groove when said rigid fingersare in a non-displaced position, and wherein displacing said pluralityof rigid fingers toward said interior surface of said female end of saidpipe further comprises displacing said free distal end into an area ofsaid interior circumferential groove defined by said top surface of saidshoulder and said first side wall.